1. Field
One embodiment of the invention relates to a measuring method and measuring apparatus of pupil transmittance distribution, an exposure method and exposure apparatus, and a device manufacturing method. More particularly, the present invention relates to measurement of a pupil transmittance distribution of a projection optical system mounted on an exposure apparatus used, for example, in manufacturing devices such as semiconductor devices or liquid crystal display devices by a photolithography process.
2. Description of the Related Art
The photolithography process for manufacture of the semiconductor devices and others is carried out using an exposure apparatus for implementing projection exposure to project a pattern image on a mask (or a reticle) onto a photosensitive substrate (a wafer or a glass plate coated with a photoresist, or the like) through a projection optical system. There is a recently proposed method of measuring a pupil transmittance distribution of the projection optical system in a mounted state on the exposure apparatus on an as-needed basis, in order to improve the contrast of the pattern image formed through the projection optical system (e.g., cf. Kazuya Sato et al., “Measurement of transmittance variation of projection lenses depending on the light paths using a grating-pinhole mask,”Proceedings of SPIE Vol. 4346, pp. 379-386, 2001).